The Data Inventory consists of three pieces of documentation: (1) the Data Log, (2) Respondent Identifying and Contact Information, and (3) the Missing Data Log.

The Data Log provides a quick reference to the data collected at each phase of a longitudinal project. As such, it gives a general overview of the structure of the project.

The Respondent Identifying and Contact Information contains information on the identity and location of the respondents in the study. Essential information includes that which is needed to contact the respondent and information to aid in locating respondents after a period of time. Other information may include the extent of completion of each component of each phase of data collection. Since this file contains confidential information about the respondents, it should be password protected and have only limited access to ensure respondent privacy.

The PAIR Project Respondent Identifying and Contact Information is maintained in Paradox for Windows since this allows querying the data and easy transfer of information to WordPerfect when creating "personalized form letters." As with other datafiles, this database should be considered a data file and, as such, needs a codebook to indicate how data should be entered.

The Missing Data Log is maintained as data are collected and updated to its final version prior to constructing the final codebook. This log gives information on which questionnaires each respondent answered and whether any questions were omitted. If data are missing, efforts should be made to elicit the information. If this is not possible, the reasons why the data are missing should be logged. This information is crucial to adequately describing the sample for various publications and presentations.